1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Native support for the I/O-Warrior USB devices
4 *
5 * Copyright (c) 2003-2005, 2020 Code Mercenaries GmbH
6 * written by Christian Lucht <lucht@codemercs.com> and
7 * Christoph Jung <jung@codemercs.com>
8 *
9 * based on
10
11 * usb-skeleton.c by Greg Kroah-Hartman <greg@kroah.com>
12 * brlvger.c by Stephane Dalton <sdalton@videotron.ca>
13 * and Stephane Doyon <s.doyon@videotron.ca>
14 *
15 * Released under the GPLv2.
16 */
17
18#include <linux/module.h>
19#include <linux/usb.h>
20#include <linux/slab.h>
21#include <linux/sched.h>
22#include <linux/mutex.h>
23#include <linux/poll.h>
24#include <linux/usb/iowarrior.h>
25
26#define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
27#define DRIVER_DESC "USB IO-Warrior driver"
28
29#define USB_VENDOR_ID_CODEMERCS 1984
30/* low speed iowarrior */
31#define USB_DEVICE_ID_CODEMERCS_IOW40 0x1500
32#define USB_DEVICE_ID_CODEMERCS_IOW24 0x1501
33#define USB_DEVICE_ID_CODEMERCS_IOWPV1 0x1511
34#define USB_DEVICE_ID_CODEMERCS_IOWPV2 0x1512
35/* full speed iowarrior */
36#define USB_DEVICE_ID_CODEMERCS_IOW56 0x1503
37/* fuller speed iowarrior */
38#define USB_DEVICE_ID_CODEMERCS_IOW28 0x1504
39#define USB_DEVICE_ID_CODEMERCS_IOW28L 0x1505
40#define USB_DEVICE_ID_CODEMERCS_IOW100 0x1506
41
42/* OEMed devices */
43#define USB_DEVICE_ID_CODEMERCS_IOW24SAG 0x158a
44#define USB_DEVICE_ID_CODEMERCS_IOW56AM 0x158b
45
46/* Get a minor range for your devices from the usb maintainer */
47#ifdef CONFIG_USB_DYNAMIC_MINORS
48#define IOWARRIOR_MINOR_BASE 0
49#else
50#define IOWARRIOR_MINOR_BASE 208 // SKELETON_MINOR_BASE 192 + 16, not official yet
51#endif
52
53/* interrupt input queue size */
54#define MAX_INTERRUPT_BUFFER 16
55/*
56 maximum number of urbs that are submitted for writes at the same time,
57 this applies to the IOWarrior56 only!
58 IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
59*/
60#define MAX_WRITES_IN_FLIGHT 4
61
62MODULE_AUTHOR(DRIVER_AUTHOR);
63MODULE_DESCRIPTION(DRIVER_DESC);
64MODULE_LICENSE("GPL");
65
66static struct usb_driver iowarrior_driver;
67
68/*--------------*/
69/* data */
70/*--------------*/
71
72/* Structure to hold all of our device specific stuff */
73struct iowarrior {
74 struct mutex mutex; /* locks this structure */
75 struct usb_device *udev; /* save off the usb device pointer */
76 struct usb_interface *interface; /* the interface for this device */
77 unsigned char minor; /* the starting minor number for this device */
78 struct usb_endpoint_descriptor *int_out_endpoint; /* endpoint for reading (needed for IOW56 only) */
79 struct usb_endpoint_descriptor *int_in_endpoint; /* endpoint for reading */
80 struct urb *int_in_urb; /* the urb for reading data */
81 unsigned char *int_in_buffer; /* buffer for data to be read */
82 unsigned char serial_number; /* to detect lost packages */
83 unsigned char *read_queue; /* size is MAX_INTERRUPT_BUFFER * packet size */
84 wait_queue_head_t read_wait;
85 wait_queue_head_t write_wait; /* wait-queue for writing to the device */
86 atomic_t write_busy; /* number of write-urbs submitted */
87 atomic_t read_idx;
88 atomic_t intr_idx;
89 atomic_t overflow_flag; /* signals an index 'rollover' */
90 int present; /* this is 1 as long as the device is connected */
91 int opened; /* this is 1 if the device is currently open */
92 char chip_serial[9]; /* the serial number string of the chip connected */
93 int report_size; /* number of bytes in a report */
94 u16 product_id;
95 struct usb_anchor submitted;
96};
97
98/*--------------*/
99/* globals */
100/*--------------*/
101
102#define USB_REQ_GET_REPORT 0x01
103//#if 0
104static int usb_get_report(struct usb_device *dev,
105 struct usb_host_interface *inter, unsigned char type,
106 unsigned char id, void *buf, int size)
107{
108 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
109 USB_REQ_GET_REPORT,
110 USB_DIR_IN | USB_TYPE_CLASS |
111 USB_RECIP_INTERFACE, value: (type << 8) + id,
112 index: inter->desc.bInterfaceNumber, data: buf, size,
113 USB_CTRL_GET_TIMEOUT);
114}
115//#endif
116
117#define USB_REQ_SET_REPORT 0x09
118
119static int usb_set_report(struct usb_interface *intf, unsigned char type,
120 unsigned char id, void *buf, int size)
121{
122 return usb_control_msg(interface_to_usbdev(intf),
123 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
124 USB_REQ_SET_REPORT,
125 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
126 value: (type << 8) + id,
127 index: intf->cur_altsetting->desc.bInterfaceNumber, data: buf,
128 size, timeout: 1000);
129}
130
131/*---------------------*/
132/* driver registration */
133/*---------------------*/
134/* table of devices that work with this driver */
135static const struct usb_device_id iowarrior_ids[] = {
136 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
137 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
138 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
139 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
140 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
141 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24SAG)},
142 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56AM)},
143 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28)},
144 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28L)},
145 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW100)},
146 {} /* Terminating entry */
147};
148MODULE_DEVICE_TABLE(usb, iowarrior_ids);
149
150/*
151 * USB callback handler for reading data
152 */
153static void iowarrior_callback(struct urb *urb)
154{
155 struct iowarrior *dev = urb->context;
156 int intr_idx;
157 int read_idx;
158 int aux_idx;
159 int offset;
160 int status = urb->status;
161 int retval;
162
163 switch (status) {
164 case 0:
165 /* success */
166 break;
167 case -ECONNRESET:
168 case -ENOENT:
169 case -ESHUTDOWN:
170 return;
171 default:
172 goto exit;
173 }
174
175 intr_idx = atomic_read(v: &dev->intr_idx);
176 /* aux_idx become previous intr_idx */
177 aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
178 read_idx = atomic_read(v: &dev->read_idx);
179
180 /* queue is not empty and it's interface 0 */
181 if ((intr_idx != read_idx)
182 && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
183 /* + 1 for serial number */
184 offset = aux_idx * (dev->report_size + 1);
185 if (!memcmp
186 (p: dev->read_queue + offset, q: urb->transfer_buffer,
187 size: dev->report_size)) {
188 /* equal values on interface 0 will be ignored */
189 goto exit;
190 }
191 }
192
193 /* aux_idx become next intr_idx */
194 aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
195 if (read_idx == aux_idx) {
196 /* queue full, dropping oldest input */
197 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
198 atomic_set(v: &dev->read_idx, i: read_idx);
199 atomic_set(v: &dev->overflow_flag, i: 1);
200 }
201
202 /* +1 for serial number */
203 offset = intr_idx * (dev->report_size + 1);
204 memcpy(dev->read_queue + offset, urb->transfer_buffer,
205 dev->report_size);
206 *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
207
208 atomic_set(v: &dev->intr_idx, i: aux_idx);
209 /* tell the blocking read about the new data */
210 wake_up_interruptible(&dev->read_wait);
211
212exit:
213 retval = usb_submit_urb(urb, GFP_ATOMIC);
214 if (retval)
215 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
216 __func__, retval);
217
218}
219
220/*
221 * USB Callback handler for write-ops
222 */
223static void iowarrior_write_callback(struct urb *urb)
224{
225 struct iowarrior *dev;
226 int status = urb->status;
227
228 dev = urb->context;
229 /* sync/async unlink faults aren't errors */
230 if (status &&
231 !(status == -ENOENT ||
232 status == -ECONNRESET || status == -ESHUTDOWN)) {
233 dev_dbg(&dev->interface->dev,
234 "nonzero write bulk status received: %d\n", status);
235 }
236 /* free up our allocated buffer */
237 usb_free_coherent(dev: urb->dev, size: urb->transfer_buffer_length,
238 addr: urb->transfer_buffer, dma: urb->transfer_dma);
239 /* tell a waiting writer the interrupt-out-pipe is available again */
240 atomic_dec(v: &dev->write_busy);
241 wake_up_interruptible(&dev->write_wait);
242}
243
244/*
245 * iowarrior_delete
246 */
247static inline void iowarrior_delete(struct iowarrior *dev)
248{
249 dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
250 kfree(objp: dev->int_in_buffer);
251 usb_free_urb(urb: dev->int_in_urb);
252 kfree(objp: dev->read_queue);
253 usb_put_intf(intf: dev->interface);
254 kfree(objp: dev);
255}
256
257/*---------------------*/
258/* fops implementation */
259/*---------------------*/
260
261static int read_index(struct iowarrior *dev)
262{
263 int intr_idx, read_idx;
264
265 read_idx = atomic_read(v: &dev->read_idx);
266 intr_idx = atomic_read(v: &dev->intr_idx);
267
268 return (read_idx == intr_idx ? -1 : read_idx);
269}
270
271/*
272 * iowarrior_read
273 */
274static ssize_t iowarrior_read(struct file *file, char __user *buffer,
275 size_t count, loff_t *ppos)
276{
277 struct iowarrior *dev;
278 int read_idx;
279 int offset;
280
281 dev = file->private_data;
282
283 /* verify that the device wasn't unplugged */
284 if (!dev || !dev->present)
285 return -ENODEV;
286
287 dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
288 dev->minor, count);
289
290 /* read count must be packet size (+ time stamp) */
291 if ((count != dev->report_size)
292 && (count != (dev->report_size + 1)))
293 return -EINVAL;
294
295 /* repeat until no buffer overrun in callback handler occur */
296 do {
297 atomic_set(v: &dev->overflow_flag, i: 0);
298 if ((read_idx = read_index(dev)) == -1) {
299 /* queue empty */
300 if (file->f_flags & O_NONBLOCK)
301 return -EAGAIN;
302 else {
303 //next line will return when there is either new data, or the device is unplugged
304 int r = wait_event_interruptible(dev->read_wait,
305 (!dev->present
306 || (read_idx =
307 read_index
308 (dev)) !=
309 -1));
310 if (r) {
311 //we were interrupted by a signal
312 return -ERESTART;
313 }
314 if (!dev->present) {
315 //The device was unplugged
316 return -ENODEV;
317 }
318 if (read_idx == -1) {
319 // Can this happen ???
320 return 0;
321 }
322 }
323 }
324
325 offset = read_idx * (dev->report_size + 1);
326 if (copy_to_user(to: buffer, from: dev->read_queue + offset, n: count)) {
327 return -EFAULT;
328 }
329 } while (atomic_read(v: &dev->overflow_flag));
330
331 read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
332 atomic_set(v: &dev->read_idx, i: read_idx);
333 return count;
334}
335
336/*
337 * iowarrior_write
338 */
339static ssize_t iowarrior_write(struct file *file,
340 const char __user *user_buffer,
341 size_t count, loff_t *ppos)
342{
343 struct iowarrior *dev;
344 int retval = 0;
345 char *buf = NULL; /* for IOW24 and IOW56 we need a buffer */
346 struct urb *int_out_urb = NULL;
347
348 dev = file->private_data;
349
350 mutex_lock(&dev->mutex);
351 /* verify that the device wasn't unplugged */
352 if (!dev->present) {
353 retval = -ENODEV;
354 goto exit;
355 }
356 dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
357 dev->minor, count);
358 /* if count is 0 we're already done */
359 if (count == 0) {
360 retval = 0;
361 goto exit;
362 }
363 /* We only accept full reports */
364 if (count != dev->report_size) {
365 retval = -EINVAL;
366 goto exit;
367 }
368 switch (dev->product_id) {
369 case USB_DEVICE_ID_CODEMERCS_IOW24:
370 case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
371 case USB_DEVICE_ID_CODEMERCS_IOWPV1:
372 case USB_DEVICE_ID_CODEMERCS_IOWPV2:
373 case USB_DEVICE_ID_CODEMERCS_IOW40:
374 /* IOW24 and IOW40 use a synchronous call */
375 buf = memdup_user(user_buffer, count);
376 if (IS_ERR(ptr: buf)) {
377 retval = PTR_ERR(ptr: buf);
378 goto exit;
379 }
380 retval = usb_set_report(intf: dev->interface, type: 2, id: 0, buf, size: count);
381 kfree(objp: buf);
382 goto exit;
383 case USB_DEVICE_ID_CODEMERCS_IOW56:
384 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
385 case USB_DEVICE_ID_CODEMERCS_IOW28:
386 case USB_DEVICE_ID_CODEMERCS_IOW28L:
387 case USB_DEVICE_ID_CODEMERCS_IOW100:
388 /* The IOW56 uses asynchronous IO and more urbs */
389 if (atomic_read(v: &dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
390 /* Wait until we are below the limit for submitted urbs */
391 if (file->f_flags & O_NONBLOCK) {
392 retval = -EAGAIN;
393 goto exit;
394 } else {
395 retval = wait_event_interruptible(dev->write_wait,
396 (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
397 if (retval) {
398 /* we were interrupted by a signal */
399 retval = -ERESTART;
400 goto exit;
401 }
402 if (!dev->present) {
403 /* The device was unplugged */
404 retval = -ENODEV;
405 goto exit;
406 }
407 if (!dev->opened) {
408 /* We were closed while waiting for an URB */
409 retval = -ENODEV;
410 goto exit;
411 }
412 }
413 }
414 atomic_inc(v: &dev->write_busy);
415 int_out_urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
416 if (!int_out_urb) {
417 retval = -ENOMEM;
418 goto error_no_urb;
419 }
420 buf = usb_alloc_coherent(dev: dev->udev, size: dev->report_size,
421 GFP_KERNEL, dma: &int_out_urb->transfer_dma);
422 if (!buf) {
423 retval = -ENOMEM;
424 dev_dbg(&dev->interface->dev,
425 "Unable to allocate buffer\n");
426 goto error_no_buffer;
427 }
428 usb_fill_int_urb(urb: int_out_urb, dev: dev->udev,
429 usb_sndintpipe(dev->udev,
430 dev->int_out_endpoint->bEndpointAddress),
431 transfer_buffer: buf, buffer_length: dev->report_size,
432 complete_fn: iowarrior_write_callback, context: dev,
433 interval: dev->int_out_endpoint->bInterval);
434 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
435 if (copy_from_user(to: buf, from: user_buffer, n: count)) {
436 retval = -EFAULT;
437 goto error;
438 }
439 usb_anchor_urb(urb: int_out_urb, anchor: &dev->submitted);
440 retval = usb_submit_urb(urb: int_out_urb, GFP_KERNEL);
441 if (retval) {
442 dev_dbg(&dev->interface->dev,
443 "submit error %d for urb nr.%d\n",
444 retval, atomic_read(&dev->write_busy));
445 usb_unanchor_urb(urb: int_out_urb);
446 goto error;
447 }
448 /* submit was ok */
449 retval = count;
450 usb_free_urb(urb: int_out_urb);
451 goto exit;
452 default:
453 /* what do we have here ? An unsupported Product-ID ? */
454 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
455 __func__, dev->product_id);
456 retval = -EFAULT;
457 goto exit;
458 }
459error:
460 usb_free_coherent(dev: dev->udev, size: dev->report_size, addr: buf,
461 dma: int_out_urb->transfer_dma);
462error_no_buffer:
463 usb_free_urb(urb: int_out_urb);
464error_no_urb:
465 atomic_dec(v: &dev->write_busy);
466 wake_up_interruptible(&dev->write_wait);
467exit:
468 mutex_unlock(lock: &dev->mutex);
469 return retval;
470}
471
472/*
473 * iowarrior_ioctl
474 */
475static long iowarrior_ioctl(struct file *file, unsigned int cmd,
476 unsigned long arg)
477{
478 struct iowarrior *dev = NULL;
479 __u8 *buffer;
480 __u8 __user *user_buffer;
481 int retval;
482 int io_res; /* checks for bytes read/written and copy_to/from_user results */
483
484 dev = file->private_data;
485 if (!dev)
486 return -ENODEV;
487
488 buffer = kzalloc(size: dev->report_size, GFP_KERNEL);
489 if (!buffer)
490 return -ENOMEM;
491
492 mutex_lock(&dev->mutex);
493
494 /* verify that the device wasn't unplugged */
495 if (!dev->present) {
496 retval = -ENODEV;
497 goto error_out;
498 }
499
500 dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
501 dev->minor, cmd, arg);
502
503 retval = 0;
504 io_res = 0;
505 switch (cmd) {
506 case IOW_WRITE:
507 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
508 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
509 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
510 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
511 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
512 user_buffer = (__u8 __user *)arg;
513 io_res = copy_from_user(to: buffer, from: user_buffer,
514 n: dev->report_size);
515 if (io_res) {
516 retval = -EFAULT;
517 } else {
518 io_res = usb_set_report(intf: dev->interface, type: 2, id: 0,
519 buf: buffer,
520 size: dev->report_size);
521 if (io_res < 0)
522 retval = io_res;
523 }
524 } else {
525 retval = -EINVAL;
526 dev_err(&dev->interface->dev,
527 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
528 dev->product_id);
529 }
530 break;
531 case IOW_READ:
532 user_buffer = (__u8 __user *)arg;
533 io_res = usb_get_report(dev: dev->udev,
534 inter: dev->interface->cur_altsetting, type: 1, id: 0,
535 buf: buffer, size: dev->report_size);
536 if (io_res < 0)
537 retval = io_res;
538 else {
539 io_res = copy_to_user(to: user_buffer, from: buffer, n: dev->report_size);
540 if (io_res)
541 retval = -EFAULT;
542 }
543 break;
544 case IOW_GETINFO:
545 {
546 /* Report available information for the device */
547 struct iowarrior_info info;
548 /* needed for power consumption */
549 struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
550
551 memset(&info, 0, sizeof(info));
552 /* directly from the descriptor */
553 info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
554 info.product = dev->product_id;
555 info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
556
557 /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
558 info.speed = dev->udev->speed;
559 info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
560 info.report_size = dev->report_size;
561
562 /* serial number string has been read earlier 8 chars or empty string */
563 memcpy(info.serial, dev->chip_serial,
564 sizeof(dev->chip_serial));
565 if (cfg_descriptor == NULL) {
566 info.power = -1; /* no information available */
567 } else {
568 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
569 info.power = cfg_descriptor->bMaxPower * 2;
570 }
571 io_res = copy_to_user(to: (struct iowarrior_info __user *)arg, from: &info,
572 n: sizeof(struct iowarrior_info));
573 if (io_res)
574 retval = -EFAULT;
575 break;
576 }
577 default:
578 /* return that we did not understand this ioctl call */
579 retval = -ENOTTY;
580 break;
581 }
582error_out:
583 /* unlock the device */
584 mutex_unlock(lock: &dev->mutex);
585 kfree(objp: buffer);
586 return retval;
587}
588
589/*
590 * iowarrior_open
591 */
592static int iowarrior_open(struct inode *inode, struct file *file)
593{
594 struct iowarrior *dev = NULL;
595 struct usb_interface *interface;
596 int subminor;
597 int retval = 0;
598
599 subminor = iminor(inode);
600
601 interface = usb_find_interface(drv: &iowarrior_driver, minor: subminor);
602 if (!interface) {
603 pr_err("%s - error, can't find device for minor %d\n",
604 __func__, subminor);
605 return -ENODEV;
606 }
607
608 dev = usb_get_intfdata(intf: interface);
609 if (!dev)
610 return -ENODEV;
611
612 mutex_lock(&dev->mutex);
613
614 /* Only one process can open each device, no sharing. */
615 if (dev->opened) {
616 retval = -EBUSY;
617 goto out;
618 }
619
620 /* setup interrupt handler for receiving values */
621 if ((retval = usb_submit_urb(urb: dev->int_in_urb, GFP_KERNEL)) < 0) {
622 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
623 retval = -EFAULT;
624 goto out;
625 }
626 /* increment our usage count for the driver */
627 ++dev->opened;
628 /* save our object in the file's private structure */
629 file->private_data = dev;
630 retval = 0;
631
632out:
633 mutex_unlock(lock: &dev->mutex);
634 return retval;
635}
636
637/*
638 * iowarrior_release
639 */
640static int iowarrior_release(struct inode *inode, struct file *file)
641{
642 struct iowarrior *dev;
643 int retval = 0;
644
645 dev = file->private_data;
646 if (!dev)
647 return -ENODEV;
648
649 dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
650
651 /* lock our device */
652 mutex_lock(&dev->mutex);
653
654 if (dev->opened <= 0) {
655 retval = -ENODEV; /* close called more than once */
656 mutex_unlock(lock: &dev->mutex);
657 } else {
658 dev->opened = 0; /* we're closing now */
659 retval = 0;
660 if (dev->present) {
661 /*
662 The device is still connected so we only shutdown
663 pending read-/write-ops.
664 */
665 usb_kill_urb(urb: dev->int_in_urb);
666 wake_up_interruptible(&dev->read_wait);
667 wake_up_interruptible(&dev->write_wait);
668 mutex_unlock(lock: &dev->mutex);
669 } else {
670 /* The device was unplugged, cleanup resources */
671 mutex_unlock(lock: &dev->mutex);
672 iowarrior_delete(dev);
673 }
674 }
675 return retval;
676}
677
678static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
679{
680 struct iowarrior *dev = file->private_data;
681 __poll_t mask = 0;
682
683 if (!dev->present)
684 return EPOLLERR | EPOLLHUP;
685
686 poll_wait(filp: file, wait_address: &dev->read_wait, p: wait);
687 poll_wait(filp: file, wait_address: &dev->write_wait, p: wait);
688
689 if (!dev->present)
690 return EPOLLERR | EPOLLHUP;
691
692 if (read_index(dev) != -1)
693 mask |= EPOLLIN | EPOLLRDNORM;
694
695 if (atomic_read(v: &dev->write_busy) < MAX_WRITES_IN_FLIGHT)
696 mask |= EPOLLOUT | EPOLLWRNORM;
697 return mask;
698}
699
700/*
701 * File operations needed when we register this driver.
702 * This assumes that this driver NEEDS file operations,
703 * of course, which means that the driver is expected
704 * to have a node in the /dev directory. If the USB
705 * device were for a network interface then the driver
706 * would use "struct net_driver" instead, and a serial
707 * device would use "struct tty_driver".
708 */
709static const struct file_operations iowarrior_fops = {
710 .owner = THIS_MODULE,
711 .write = iowarrior_write,
712 .read = iowarrior_read,
713 .unlocked_ioctl = iowarrior_ioctl,
714 .open = iowarrior_open,
715 .release = iowarrior_release,
716 .poll = iowarrior_poll,
717 .llseek = noop_llseek,
718};
719
720static char *iowarrior_devnode(const struct device *dev, umode_t *mode)
721{
722 return kasprintf(GFP_KERNEL, fmt: "usb/%s", dev_name(dev));
723}
724
725/*
726 * usb class driver info in order to get a minor number from the usb core,
727 * and to have the device registered with devfs and the driver core
728 */
729static struct usb_class_driver iowarrior_class = {
730 .name = "iowarrior%d",
731 .devnode = iowarrior_devnode,
732 .fops = &iowarrior_fops,
733 .minor_base = IOWARRIOR_MINOR_BASE,
734};
735
736/*---------------------------------*/
737/* probe and disconnect functions */
738/*---------------------------------*/
739/*
740 * iowarrior_probe
741 *
742 * Called by the usb core when a new device is connected that it thinks
743 * this driver might be interested in.
744 */
745static int iowarrior_probe(struct usb_interface *interface,
746 const struct usb_device_id *id)
747{
748 struct usb_device *udev = interface_to_usbdev(interface);
749 struct iowarrior *dev = NULL;
750 struct usb_host_interface *iface_desc;
751 int retval = -ENOMEM;
752 int res;
753
754 /* allocate memory for our device state and initialize it */
755 dev = kzalloc(size: sizeof(struct iowarrior), GFP_KERNEL);
756 if (!dev)
757 return retval;
758
759 mutex_init(&dev->mutex);
760
761 atomic_set(v: &dev->intr_idx, i: 0);
762 atomic_set(v: &dev->read_idx, i: 0);
763 atomic_set(v: &dev->overflow_flag, i: 0);
764 init_waitqueue_head(&dev->read_wait);
765 atomic_set(v: &dev->write_busy, i: 0);
766 init_waitqueue_head(&dev->write_wait);
767
768 dev->udev = udev;
769 dev->interface = usb_get_intf(intf: interface);
770
771 iface_desc = interface->cur_altsetting;
772 dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
773
774 init_usb_anchor(anchor: &dev->submitted);
775
776 res = usb_find_last_int_in_endpoint(alt: iface_desc, int_in: &dev->int_in_endpoint);
777 if (res) {
778 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
779 retval = res;
780 goto error;
781 }
782
783 if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
784 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
785 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
786 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
787 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
788 res = usb_find_last_int_out_endpoint(alt: iface_desc,
789 int_out: &dev->int_out_endpoint);
790 if (res) {
791 dev_err(&interface->dev, "no interrupt-out endpoint found\n");
792 retval = res;
793 goto error;
794 }
795 }
796
797 /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
798 dev->report_size = usb_endpoint_maxp(epd: dev->int_in_endpoint);
799
800 /*
801 * Some devices need the report size to be different than the
802 * endpoint size.
803 */
804 if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
805 switch (dev->product_id) {
806 case USB_DEVICE_ID_CODEMERCS_IOW56:
807 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
808 dev->report_size = 7;
809 break;
810
811 case USB_DEVICE_ID_CODEMERCS_IOW28:
812 case USB_DEVICE_ID_CODEMERCS_IOW28L:
813 dev->report_size = 4;
814 break;
815
816 case USB_DEVICE_ID_CODEMERCS_IOW100:
817 dev->report_size = 12;
818 break;
819 }
820 }
821
822 /* create the urb and buffer for reading */
823 dev->int_in_urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
824 if (!dev->int_in_urb)
825 goto error;
826 dev->int_in_buffer = kmalloc(size: dev->report_size, GFP_KERNEL);
827 if (!dev->int_in_buffer)
828 goto error;
829 usb_fill_int_urb(urb: dev->int_in_urb, dev: dev->udev,
830 usb_rcvintpipe(dev->udev,
831 dev->int_in_endpoint->bEndpointAddress),
832 transfer_buffer: dev->int_in_buffer, buffer_length: dev->report_size,
833 complete_fn: iowarrior_callback, context: dev,
834 interval: dev->int_in_endpoint->bInterval);
835 /* create an internal buffer for interrupt data from the device */
836 dev->read_queue =
837 kmalloc_array(n: dev->report_size + 1, MAX_INTERRUPT_BUFFER,
838 GFP_KERNEL);
839 if (!dev->read_queue)
840 goto error;
841 /* Get the serial-number of the chip */
842 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
843 usb_string(dev: udev, index: udev->descriptor.iSerialNumber, buf: dev->chip_serial,
844 size: sizeof(dev->chip_serial));
845 if (strlen(dev->chip_serial) != 8)
846 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
847
848 /* Set the idle timeout to 0, if this is interface 0 */
849 if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
850 usb_control_msg(dev: udev, usb_sndctrlpipe(udev, 0),
851 request: 0x0A,
852 USB_TYPE_CLASS | USB_RECIP_INTERFACE, value: 0,
853 index: 0, NULL, size: 0, USB_CTRL_SET_TIMEOUT);
854 }
855 /* allow device read and ioctl */
856 dev->present = 1;
857
858 /* we can register the device now, as it is ready */
859 usb_set_intfdata(intf: interface, data: dev);
860
861 retval = usb_register_dev(intf: interface, class_driver: &iowarrior_class);
862 if (retval) {
863 /* something prevented us from registering this driver */
864 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
865 goto error;
866 }
867
868 dev->minor = interface->minor;
869
870 /* let the user know what node this device is now attached to */
871 dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
872 "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
873 iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
874 return retval;
875
876error:
877 iowarrior_delete(dev);
878 return retval;
879}
880
881/*
882 * iowarrior_disconnect
883 *
884 * Called by the usb core when the device is removed from the system.
885 */
886static void iowarrior_disconnect(struct usb_interface *interface)
887{
888 struct iowarrior *dev = usb_get_intfdata(intf: interface);
889 int minor = dev->minor;
890
891 usb_deregister_dev(intf: interface, class_driver: &iowarrior_class);
892
893 mutex_lock(&dev->mutex);
894
895 /* prevent device read, write and ioctl */
896 dev->present = 0;
897
898 if (dev->opened) {
899 /* There is a process that holds a filedescriptor to the device ,
900 so we only shutdown read-/write-ops going on.
901 Deleting the device is postponed until close() was called.
902 */
903 usb_kill_urb(urb: dev->int_in_urb);
904 usb_kill_anchored_urbs(anchor: &dev->submitted);
905 wake_up_interruptible(&dev->read_wait);
906 wake_up_interruptible(&dev->write_wait);
907 mutex_unlock(lock: &dev->mutex);
908 } else {
909 /* no process is using the device, cleanup now */
910 mutex_unlock(lock: &dev->mutex);
911 iowarrior_delete(dev);
912 }
913
914 dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
915 minor - IOWARRIOR_MINOR_BASE);
916}
917
918/* usb specific object needed to register this driver with the usb subsystem */
919static struct usb_driver iowarrior_driver = {
920 .name = "iowarrior",
921 .probe = iowarrior_probe,
922 .disconnect = iowarrior_disconnect,
923 .id_table = iowarrior_ids,
924};
925
926module_usb_driver(iowarrior_driver);
927

source code of linux/drivers/usb/misc/iowarrior.c